This invention relates to a new and improved device to provide enhanced worker protection when workers are doing any type of work in excavations such as below ground repairs, including maintenance or installation of any type such as trenching, bore-pits, manhole installations, or pipe or pipeline maintenance work. More particularly, this invention relates to an improved shoring device, of the type having pairs of elongate rails and extendable and contractible cross braces connected at opposite ends to the rails, which device is lowered and raised into and out of below grade working sites such as into and out of a trench to a position between the trench walls, which device is adapted when extended to hold shoring shields tightly against the walls. This device can be provided with or without hydraulic extendable actuators, with or without positive locking devices, and with or without springs positioned and situated so as to collapse the cross braces and pull the shoring shields away from the walls of the trench (or other excavation). The device further relates to a new and improved method and apparatus of armored and protected hydraulic valving manifold and protected hydraulic fluid lines for use with the improved shoring device of this invention, or for use with other such hydraulic shoring devices as are presently used.
Presently available excavating equipment permits digging rapidly so that work can be done and the excavation immediately refilled. However, installations may require personnel to enter into the excavation which can be rather deep or through unstable soil, and cave-ins of the excavation not only interfere with the maintenance or construction operations, but may cause serious injury, or even loss of life to working personnel. The various types of prior art devices which are utilized in these maintenance and construction trenching or excavation shoring operations are characterized by devices of the types illustrated and described in U.S. Pat. No. 3,791,151, issued to David O. Plank Feb. 12, 1974; U.S. Pat. No. 3,224,201 issued to Brunton in December, 1965; U.S. Pat. No. 3,335,573 to Ward issued Aug. 15, 1967; U.S. Pat. No. 3,347,049 to Faltersack et. al issued Oct. 17, 1967; U.S. Pat. No. 3,851,856 to Berg issued Dec. 3, 1974; and U.S. Pat. No. 4,787,781 to Bradberry issued Nov. 29, 1988. Various types of devices of this sort are known worldwide as evidenced by Japanese Patent 1459090 for a Hydraulic Expansion Beam for a Shoring Strut in the name of Osaka Gas Company Ltd. invented by Takashi Fukumori, Maso Koide and Kenichi Fukumori issued Oct. 28, 1982. Each and all of these references are hereby incorporated by reference for all purposes.
As described in the above references there exist various types of shoring devices, usually incorporating hydraulic jack parallelogram arrangements which are used for shoring the sides of trenches or excavations. One type of common device utilizes a pair of horizontally disposed vertically spaced hydraulic cylinder and piston units pivotally connected at their opposite ends to shoring rails which extend vertically and which will be held against opposite sides of the trench when the hydraulic cylinder and piston units are expanded. Another type of common device uses a pair of horizontally disposed horizontally spaced hydraulic cylinder and piston units connected pivotally at their opposite ends to horizontal shoring rails which abut against shoring timbers or sheeting which are vertically disposed at opposite sides of the trench. Both these types operate so that the cylinder and piston units act as cross braces extending across the trench. After the devices are inserted into the trench, hydraulic fluid is pumped into the cylinders to force the pistons to extend, and thereby to jack the shoring rails apart to the desired extent, and thereby hold the shoring upright rails or shoring boards tightly against opposite walls of the trench to prevent sloughing of the material behind the boards.
Various combination hydraulic jack and piston and cylinder assemblies may be used or may be modified for use with devices according to the present invention are represented by the inventions described and claimed in U.S Pat. No. 3,224,201 to Brunton issued Dec. 21, 1965, U.S. Pat. No. 3,321,182 to Elenburg issued May 23, 1967; U.S. Pat. No. 3,851,856 to Berg issued Dec. 3, 1974; U.S. Pat. No. 3,905,279 to Yadon issued Sept. 16, 1975; U.S. Pat. No. 4,247,082 to Sjolund issued Jan. 27, 1981; and, U.S. Pat. No. 4,449,734 to Cory issued May 22, 1984, and each and all of these references are hereby incorporated by reference for all purposes.
As described by the references in the preceding paragraph, there exist various types of hydraulic jacking units which are provided with assorted positive supporting mechanisms to lock the jack into extended position of the piston and cylinder units so as to prevent retraction of the piston into the cylinder even in the event of pressure loss or release from the cylinder.
Notwithstanding the various devices referred to above and other devices known to those of skill in the art of trenching, shoring and safely working in excavations below grade, various problems associated with devices in use at present are solved by the new and improved shoring shield of the present invention. The new and improved shoring shield of the present invention provides a light weight, portable, adjustable, reuseable, preassembled shoring system that can be quickly installed and removed. Further, it provides increased strength and durability, increased rigidity, and features easier and more adaptable installation capabilities and easier, simpler and safer operating due to the improved armored manifold valving and hydraulic lines, and far superior due to the continuity and new and improved section design of the solid sheeting.
Full appreciation of the present invention and its advance of methods and devices commonly used in the art can best be appreciated as set out in more detail below with references to the accompanying drawings.